Airscrew for Toy Helicopter

ABSTRACT

The present invention relates to an airscrew for a toy helicopter, comprising a rotating shaft directly connectable to a driving mechanism of the helicopter, two airscrew blades, a balance mechanism, said two airscrew blades respectively hinged to the rotating shaft so that a blade angle of the airscrew blade is able to change during the flight. In an embodiment, a middle portion of the balance mechanism is hinged to the rotating shaft, and each of two airscrew blades has an extending member, the balance mechanism is contacted with the extending member during the swing motion, such that the blade angle of the airscrew blade is changed. The present invention has a compact structure and a stable balancing capability, therefore, the disadvantages such as easy breakage of the link is avoided and the package volume is also reduced. The connecting member between the airscrew blades as well as the balance rod and the rotating shaft is thicker and has a bigger intensity, so it is not easy to be broken due to the falling of the helicopter, therefore, it can be used in a flyable toy or a prototype aircraft, and a vertical lift aerocraft.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to and the benefit of the filing of Chinese Serial No. 2008200499611, entitled “Airscrew for Toy Helicopter”, filed on Jun. 25, 2008, and the specification and claims thereof are incorporated herein by reference.

FIELD OF INVENTION

The present invention relates to a flyable toy or a prototype aircraft, more particular, to an airscrew for the flyable toy helicopter or a prototype helicopter.

BACKGROUND OF INVENTION

A flyable electric toy helicopter is a kind of new fashion toy in recent years, since the mature developments in the battery being highly energized and the motor being microminiaturized, so that problems concerning the power for the flying and the time of the flying are solved.

However, since the helicopter has less weight and is easy to be influenced by air flow, the torsion produced by the helicopter causes a poor flying stability of the helicopter and the flying is difficult to be controlled. Especially for the beginner, it is difficult to allow the helicopter to fly up smoothly and securely.

In order to solve this problem, the Chinese Patent document (CN2848313Y) discloses an electric toy helicopter, including an airscrew unit having a balance rod and two sets of airscrews, the rotation direction of blades of two sets airscrews are reversed, the inverted rotary force caused by the rotation can be removed, so that the helicopter can flight in balance.

The Chinese Patent document (CN2848312) discloses an electric toy helicopter, which flies smoothly by employing a balance rod, coaxial and homo-directional bi-airscrews, and rotation unit to synchronically rotate. However, since the structure of the flight is too complicated due to the coaxial bi-airscrews and auxiliary rotating wing balance mechanism, a higher malfunction rate and a shorter life span occur, the angle between the rotational plane of the primary vane, the auxiliary rotating wing or the balance rod and the driving shaft is unchangeable so that effects in balance and stability are still poor.

The Chinese Patent document (CN201012293Y) discloses a helicopter having a main rotating wing and an auxiliary rotating wing; the main rotating wing is hinged on the rotating wing shaft, so that the angle between the rotational plane of the airscrew vane of the main rotating wing and the rotating wing shaft is changeable. The auxiliary rotating wing is provided with two horizontal blades mounted on a swing shaft in the relation of swing. The main rotating shaft and the auxiliary rotating wing are connected to each other by a mechanical connecting rod. The swing motion of the auxiliary rotating wing controls the incidence angle of the airscrew blade of the main rotating wing.

The helicopter is designed that the angle between the rotational plane of the airscrew blade of the main rotating wing and the rotating wing shaft being is changeable during flying, so that the flight stability is greatly improved.

However, the auxiliary rotating wing is located above the main rotating wing, so that the size of the helicopter is too large, the mechanical connecting bar for connecting the main rotating wing and the auxiliary rotating wing is easily to be broken or fallen off, and the horizontal blade of the auxiliary rotating wing will bring a larger resistance during the flight, so that is not good for playing.

The Chinese Patent document (CN1944187Y) discloses a balance mechanism of the remote coaxial typed bi-rotating wings prototype helicopter, which includes a balance rod, an upper rotating wing blade clip and an upper link. The upper rotating wing blade clip is hinged to a driving shaft. The upper link is connected to the balance rod and the upper rotating wing blade clip. A plurality of bell crank heads are provided on the balance rod or the upper rotating wing blade clip and the upper link connects an upper balance rod and the bell crank head so that the connected position of the upper link can be adjustable, and the length of the arm of the balance force is changeable. Therefore, the stability of the balance mechanism is improved, the manipulator can select the connected position in accordance with the proficiency, and thereby the eligible balancing requirements are reached.

However, the link is easily to be broken and damaged, and the balance rod is located above the rotating wing blade so that the size of the helicopter is too big, thereby it is difficult for the beginner to handle the connection position of the link.

SUMMARY OF INVENTION

Accordingly, the first object of present invention is provides an airscrew for a toy helicopter, which can obtain a stable balance without a link, so that the shortage of the easy broken of the link is avoided.

In order to achieve the object of the present invention, the airscrew for the toy helicopter of the present invention comprising: a rotating shaft directly connectable to a driving mechanism of the helicopter, two airscrew blades, a balance mechanism, characterized in that, a middle portion of the balance mechanism being hinged to the rotating shaft, each of two airscrew blades has an extending member hung on the balance mechanism.

The balance mechanism can be a balance rod which the weight of an end portion is larger than a middle portion thereof or an auxiliary rotating wing having a blade-shaped wing panel at the end portion thereof.

Preferably, the two airscrew blades are respectively hinged to the rotating shaft so that a blade angle of the airscrew blade is able to change during the flight.

A connecting member is further provided between two of airscrew blades, both ends of said connecting member are respectively provided with a tenon and a fork lever, and the airscrew blade has a hole corresponding with said tenon, and the fork lever is wedged below the airscrew blade.

A hinge shaft sleeve at the middle portion of the balance mechanism may be coplanar with the hinge shaft of the airscrew blade. Further, an angle in a range of 20-90° is formed between the axes of the hinge shaft sleeve at the middle portion of the balance mechanism and the axes of the hinge shaft of the airscrew blade.

The present invention has a compact structure and a stable balancing capability, therefore, the drawbacks such as easy breakage of the link are avoided and the package volume is also reduced. The connecting member between the airscrew blades as well as the balance rod and the rotating shaft is thicker and has a bigger intensity, so it is not easy to be broken due to the falling of the helicopter, therefore, it can be used in a flyable toy or a prototype aircraft, and a vertical lift aerocraft.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is an exploded view of the helicopter according to one embodiment of the present invention;

FIG. 2 is a sectional view of the embodiment of the present invention of FIG. 1;

FIG. 3 is a front view of the embodiment of the present invention of FIG. 1; and

FIG. 4 is a top view of the embodiment of the present invention of FIG. 1.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Preferred embodiments of the present invention will be described hereinafter in detail with reference to the attached drawings, wherein the like reference numerals refer to the like elements throughout the specification. The present invention may, however, be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein; rather, these embodiments are provided so that the present disclosure will be thorough and complete, and will fully convey the concept of the invention to those skilled in the art.

As shown in FIG. 1, an end portion of a rotating shaft 1 directly connected with a helicopter driving mechanism has a balance rod shaft sleeve 2 and airscrew blade hinge shafts 3, 4, such airscrew blade hinge shaft 3, 4 are distributed symmetrically with each other in a line. In an example, an angle between the projection of the axes of the balance rod shaft sleeve 2 on the vertical plane of the rotating shaft 1 and the projection of axes of airscrew blade hinge shafts 3, 4 on the vertical plane of the rotating shaft 1 is in a range between 20-90°, so that a proper alternate angle is formed between the balance rod and airscrew blade hinge shafts 3, 4, thereby, the swing of the balance rod in a vertical direction is able to change the blade angle of the airscrew blade. The balance rod shaft sleeve 2 and airscrew blade hinge shafts 3, 4 can be provided either in the same plane or the different planes.

The balance rod 5 is curved in the middle portion and formed into a shaft bush 6, the hinge 7 is penetrated through the shaft bush 6 of the balance rod 5 and the balance rod shaft sleeve 2 of the rotating shaft 1, so that the balance rod 5 is hinged with the rotating shaft 1, thereby, an angle between the rotating plane of the balance rod 5 and the rotating shaft is freely changed. Each of both ends of the balance rod 5 have a weighted portion 8 or a bigger volume, so that weight of the ends of the balance rod 5 is significantly greater than the middle portion thereof to improve the balancing effects. The portion of balance rod 5 having the weighted portion also can be replaced by a blade-shaped auxiliary rotating wing, which has the same balancing effects as above.

Each of airscrew blades 9, 10 has shaft holes 11, 12 at the root portion thereof, airscrew blade hinge shafts 3, 4 are respectively hinged into the corresponding shaft holes 11, 12 of airscrew blades 9, 10. A connection member 15 is connected between airscrew blades 9, 10. Tenons 16, 17, as well as fork levers 18, 19 are respectively provided at both ends of the connection member 15. Airscrew blades 9, 10 have holes 20 and 21 corresponding to tenons 16, 17, and tenons 16, 17 are correspondently inserted into holes 20, 21, respectively. Fork levers 18, 19 are wedged below the airscrew blades 9, 10. Two airscrew blades 9, 10 are fixed by means of the connection member 15 and hinged on the rotating shaft 1 through air screw blade hinge shafts 3, 4, so that blade angles of two airscrew blades can be freely changed, but in opposite directions. More specifically, if one blade angle of the airscrew blade is increased by the impact caused by outside airflow, another blade angle of the airscrew blade is caused to reduce. On the contrary, if one blade angle of the airscrew blade is reduced by the impact caused by outside airflow, another blade angle of the airscrew blade is increased.

Extending members 13, 14 are fixedly connected to lateral positions at root portions of airscrew blades 9, 10, and the extending members 13, 14 are hung on the balance rod 5 and slightly press the balance rod 5. Blade angles of airscrew blades are driven to swing by the balance rod 5 swinging up and down. During the flight, when two airscrew blades bring out the same lift force, the helicopter will flight smoothly. Blade angles of two airscrew blades will be changed where the helicopter is under an unstable condition due to the interference of outside airflow. For example, if one of airscrew blades is impacted by a downward airflow impact and the blade angle thereof become larger, the blade angle of another airscrew blade become smaller immediately to reduce lift force. At this time, since the rotating plane of the airscrew blade is offset from the vertical plane of the rotating shaft 1, a linkage between the balance rod and the airscrew blade causes the rotating plane of the balance rod to be not vertical to the rotating shaft 1, and centrifugal force of the rotation of the balance rod requires the rotating plane thereof to be restored back to the vertical plane of the rotating shaft 1 quickly. As a result, the rotating plane of the airscrew blade is pulled back to the vertical plane of the rotating shaft 1, and the blade angle of the airscrew blade at both sides is also restored to the original state to keep the helicopter smoothly flying. On the contrary, if one of airscrew blade is encountered with an upward airflow impact and the blade angle thereof becomes smaller, the blade angle of the other airscrew blade becomes larger immediately and the lift force is increased, the balance rod also has the similar linkage so that blade angles of airscrew blades at both sides are back to the original state, thereby the helicopter is kept to fly smoothly.

It would be appreciated by those skilled in the art that many modifications, alterations and substitutions may be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the claims and their equivalents. 

1. An airscrew for a toy helicopter, comprising: a rotating shaft directly connectable to a driving mechanism of the helicopter, two airscrew blades, a balance mechanism, said two airscrew blades being hinged to the rotating shaft respectively so that a blade angle of the airscrew blade is able to change during the flight, characterized in that, a middle portion of the balance mechanism being hinged to the rotating shaft, each of two airscrew blades has an extending member, the balance mechanism is contacted with the extending member during the swing motion, such that the blade angle of the airscrew blade is changed.
 2. The airscrew for the toy helicopter according to claim 1, characterized in that, said extending member is hung on the balance mechanism.
 3. The airscrew for the toy helicopter according to claim 1, characterized in that, said balance mechanism is a balance rod which the weight of an end portion is larger than a middle portion thereof.
 4. The airscrew for the toy helicopter according to claim 1, characterized in that, said balance mechanism is an auxiliary rotating wing having a blade-shaped wing panel at the end portion thereof.
 5. The airscrew for the toy helicopter according to claim 1, characterized in that, a hinge shaft sleeve at the middle portion of the balance mechanism is coplanar with the hinge shaft of the airscrew blade.
 6. The airscrew for the toy helicopter according to claim 5, characterized in that, an angle in a range of 20-90° is formed between the axes of the hinge shaft sleeve at the middle portion of the balance mechanism and the axes of the hinge shaft of the airscrew blade.
 7. The airscrew for the toy helicopter according to claim 1, characterized in that, a connecting member is provided between two of airscrew blades, both ends of said connecting member are respectively provided with a tenon and a fork lever, and the airscrew blade has a hole corresponding with said tenon, the tenon is inserted into the hole, and the fork lever is wedged below the airscrew blade. 